光谱选择性稀土钙钛矿/MXenes复合材料的可控构建及光热转换性能研究

Developing and designing high-efficiency solar-thermal materials is regarded as one of the most promising researches in the field of solar-thermal evaporation for seawater desalination. Carbon-based and plasmonic-based materials that have been developed and explored have broadband solar absorption, but their high thermal radiation limit the enhancement of solar thermal conversion efficiency..In consideration of this disadvantage, we propose the micro/nanostructure design of rare-earth perovskite oxides and 2D layered MXene nanosheets, which can effectively adjust the optical and thermal properties, simultaneously absorb solar radiation into heat and minimize thermal radiation loss. Developing the nanocomposite hybridization strategy by in-situ growth methods will help construct perovskite oxide/MXene nanocomposites with well-defined morphologies and stable interfaces. Furthermore, the synergistic effect between spectrally selective absorption perovskites and MXene with surface plasmon resonance will enhance solar-thermal conversion efficiency of composites. Systematic investigations on surface chemistry of the solar absorber and thermal insulator on both the dynamic evaporation behaviour and equilibrium evaporation performance enable to deeper understanding of the processes of solar energy conversion, energy transport, mass transport and vapour diffusion kinetics at the interface. In addition, rational calculation standards of evaporation efficiency will be well summarized to reveal the relationships among the preparation methods, adjustable mechanism of structure/morphology and solar-thermal properties of composites. Novel preparation techniques and multiple dimensional structures of composites will be also intensely constructed and explored. Through the implementation of this proposal, it is expected to provide useful reference and database for the development and solar-driven interfacial evaporation application of solar-thermal nanocomposites with unique efficiency.

高效光热材料的设计开发是近年来太阳能光热蒸发海水淡化领域的研究前沿与热点。目前研究的碳材料及等离子体金属纳米材料虽实现对太阳光的宽光谱吸收，但其较高的热辐射损失制约了光热效率的提升。本项目拟借助原位生长复合策略，利用多维度稀土钙钛矿型钴氧化物与二维Ti3C2Tx的微纳结构可控设计，构筑形貌可控、稳定结合的界面；通过其光学与热学的有效调控，优化钙钛矿的光谱选择性吸收特性与Ti3C2Tx的等离子体共振效应的协同作用，将太阳能充分吸收，并降低热辐射损失，提高复合材料的光热转化效率。归纳合理的效率计算方法，探究材料表面化学对蒸发行为和平衡蒸发性能的影响，深入理解界面处太阳能转化、质量传输、蒸汽扩散动力学过程；揭示复合材料的可控制备方法—结构与形态调控机制—光热性能之间的内在联系，发展构筑多维度复合光热材料的新方法，为高效界面光热材料在光热海水淡化领域的应用奠定理论和实践基础。

在“碳达峰、碳中和”国家重大战略指引下，亟需探索和开发新型的清洁、高效可持续能源，促进生态环境与绿色能源的协调可持续发展。然而，太阳能转换过程中涉及到光能利用率低、转换能量损失等问题，如何提高能量转换效率及利用率是目前面临的主要挑战之一。近年来，申请人围绕太阳能光热转换界面调控的关键科学问题，以提升太阳能转化效率为目标，开展了光热材料的可控制备、表界面调控和能量转换机理研究。基于二维Ti3C2 MXene和rGO表面丰富官能团间的静电作用，发展了静电自组装互穿网络结构策略，在聚乙烯醇(PVA)和壳聚糖(CS)聚合物交联网络中引入二维界面限域空间，实现了对水凝胶内部水分子间氢键的扰动，建立并发展了多维度纳米空间限域界面调控水分子行为与相变的方法。该蒸发器获得了3.62kg/m2/h，超出了二维蒸发器在1个太阳光下的蒸发极限值。并且，申请人将光催化降解有机污染物功能引入到光热蒸汽转化技术中，利用界面自组装策略原位构筑多维度四氧化三钴(Co3O4) /二维Ti3C2 MXene以及钙钛矿/MXene催化复合纳米材料，优化界面能量与质量传递效率，在光热蒸发的同时实现了对盐酸四环素接近100%的降解效率，达到高效的光热蒸发协同催化效果。通过对稀土钙钛矿氧化物及无机二维纳米材料的精确界面构筑、组分结构调控、表面改性等手段，揭示了太阳能到热能和化学能转换过程中的材料构效关系及调控规律，为高效太阳能转化的材料开发和体系构建提供了新思路。与此同时，申请人开发并设计了多种光热蒸发器热工程结构增强光热蒸汽转化效率，揭示了结构调控对光热蒸发过程中能量转化与传输的影响规律，通过界面能量管理策略显著增强光热蒸汽转化效率。在该项目的支持下，申请人在ACS Nano、Nano Energy、Sci. Bull.等期刊上共发表学术论文11篇，3年内论文被引用超400次，其中3篇被评为ESI 1%高被引论文；授权和申请中国发明专利6项，授权2项。